How to determine the number and layout of FFU in a medical device clean workshop?

Direct answer: First divide the areas that require clean air supply according to the production process, and determine the cleanliness target and design air volume of each area; then select the FFU that reaches the target air volume under the specified filter and project resistance, calculate the preliminary number of units based on the air volume, and adjust the layout based on equipment location, personnel logistics, and return air paths. The final number of units should be confirmed by on-site air volume, airflow distribution and cleanliness tests.

The products and processes of medical devices are different, and the regional requirements of the clean workshop may also be different. Production, assembly, packaging and personnel and material channels should be planned separately according to actual pollution control needs. According to ISO 14644-1, air cleanliness levels are classified based on suspended particle concentration and cannot be directly converted into a fixed number of FFU.

Draw the process area first, then arrange the FFU

Mark the product exposure location, production equipment, personnel activity range, material inlet and return air outlet on the floor plan. The focus of the layout is to obtain appropriate air supply to the process location that needs to be protected and to enable the airflow to return according to the designed path.

FFU should not be evenly arranged only on the suspended ceiling. If the equipment blocks the air supply, there is frequent traffic at the door, or the return air path is not smooth, and the number of units meets the calculation results, the local airflow may still be insufficient. Ceiling beams, lighting fixtures, sprinklers and inspection openings should also be put into the layout plan at the same time.

The number of units is calculated using 'effective air volume under project conditions'

In each area, the number of units can be estimated by using the regional design air supply volume ÷ the effective air volume of a single FFU , and the result is rounded up. The effective air volume of a single unit should come fromFFU complete machine assembly specifiedHEPA or ULPA filter , data at design gear and resistance conditions, rather than the product's nominal maximum air volume.

Then check whether the initially calculated number of units can cover the key process positions, whether the air outlet is uniform, and whether the return air volume and the pressure difference in adjacent areas meet the design. If the air volume is sufficient but there are weak airflow areas at key locations, the specifications, location, or return air organization should be adjusted first before deciding whether to increase the number of units.

After the layout is determined, what results need to be verified?

During the prototype stage, the size, filter sealing, performance and control method of a single FFU at the target air volume should be confirmed. After installation, the actual air volume, airflow distribution and cleanliness of each area should be checked separately, and the operating status during the test should be noted. ISO 14644-3 provides a framework of performance testing methods for clean rooms and clean areas; specific test items should be determined in conjunction with product processes and project technical documents.

Larger workshops should also map the FFU layout to the power supply and control zones. When unified speed regulation or status monitoring is needed, planning can be done in advanceFFU group control system avoids adjusting addresses and wiring after the equipment arrangement is completed.

Aili Industrial's fans, motors, control systems, sheet metal and filters are all self-produced and self-developed, and can be matched to the FFU complete machine based on the ceiling module, process area, target air volume and control requirements of the medical device workshop. For batch projects, it is recommended to confirm the prototype and partition layout first, and then conduct on-site verification according to the technical agreement. Specific specifications, quantity and layout are subject to project conditions and test results.